So you have chosen to go the battery-powered weed eater route. Well, good choice. They are definitely easier to handle and are better for the wallet than the gas-powered weed eaters. But unfortunately, they still have their set of problems that can make them stop working. So much for not having to do mechanical work on battery-powered weed eaters.
Well, thankfully, there are only a few things that can cause battery-operated weed eaters to stop working. Let’s take a look at what the problems are.
Why Has My Battery Operated Weed Eater Stopped Working? (The Short Explanation/Answer)
If your battery-operated weed eater stopped working, then there is likely an issue with the battery, motor, or electrical circuit in between. This can include the following problems with your battery-powered weed eater.
- Damaged Battery
- Poor Battery Connection
- Broken Trigger Switch
- Bad Motor Connections
- Worn Out Motor Brushes
A Closer Look at Possible Reasons a Battery Weed Eater May Stop Working
To diagnose why your battery weed eater is broken, you’ll need to grab a couple of screwdrivers and a multimeter. With these tools, you’ll be able to get into the weed eater and start doing some tests. But first, let me go over the basics of how a weed eater is wired so you know what to look for.
The Basic Wiring of a Battery-Operated Weed Eater
The battery of a battery-operated weed eater is connected by two wires. One wire goes to the motor, and the other goes to the trigger. The trigger is connected to the motor with another wire.
Finally, the connections at the motor are transferred to the inner winding of the electric motor via the brushes. This is all there is to it. You might have a battery indicator on your weed eater that falls between the circuit, but this shouldn’t affect how the weed eater operates.
So, now that you know the basic electrical circuit of your weed eater, let’s figure out where on the circuit your battery-operated weed eater stopped working.
Just because your battery charger is saying that the battery is charged doesn’t mean it actually is. So, grab your multimeter and test the battery voltage. You’ll first want to set the voltage on the multimeter to DC, then connect the probes to the battery.
Next, compare the voltage reading from the meter and compare it to the battery. For example, if you have an 18v battery, the meter should read this number or slightly above. Then you’ll need to check the battery under load. Even if a battery has voltage, it could still be dead and isn’t going to power your weed eater.
So, you need to place a resistor in parallel with the battery. If your battery still shows the same voltage when under load, then it’s good. If the voltage drops under load, then it’s either dead or not charged properly.
Poor Battery Connection
All battery-operated weed eater manuals state that you must keep the inside of the battery housing dry. If you don’t, the terminals could get corroded. In addition to corrosion, terminals are usually spring-loaded so that a solid connection can be made.
So, remove the battery and check for any corrosion and if there is an issue with the spring-loaded connection. You want to make sure that nothing is blocking the connection.
Broken Trigger Switch
In the back of the trigger, you’ll find a switch that converts the action of pulling the trigger into an electrical connection. So, if you place your multimeter on either side of the switch and then pull the trigger, you should be able to read the voltage from the battery. If you don’t, then it means the switch is probably bad.
Bad Motor Connections
The next item to check is the connections from the battery and trigger switch to the motor. The weed whacker head experiences a lot of vibration, and this can loosen the connection. So, before you grab your tester, make sure the connectors are snuggly in place.
Then, you want to check for any corrosion. Again, the connections can become corroded and stop the electricity from flowing through the electrical circuit. Place the probes on either side of the connection, then pull the trigger. If there is an issue with the connection, then your tester will not show the same load voltage it did when you directly tested the battery.
Worn Out Motor Brushes
The first thing you’ll want to inspect are the motor brushes. These are the 2 spring loads connected from the motor terminal to the inner windings of the motor. The brushes are needed because the spinning motion of the motor would make a fixed wire connection coil up and snap in a second or two.
These brushes press against the motor as it spins and transfer the power from the battery. So, every time the motor spins, the brushes wear down. After a while, they’ll wear down to a point where they no longer work.
On most battery-powered garden equipment, including weed whackers, these brushes are easily removed. So, pop yours out and see how much is left on each. If they are worn out too much, you need to replace them both.
How to Fix a Battery-Operated Weed Eater That Has Stopped Working
If your cordless weed eater stopped working, you need to carry out a repair. Well, as long as you managed to diagnose the issue. Now, depending on your particular weed whacker, you might get lucky and be able to find the spare part you need.
But unfortunately, not all manufacturers provide the part you need, and you’ll need to send the tool in for repairs. So, do your research and check that the parts you need are available for purchase. Ok, let’s look at how you can repair your cordless weed eater that stopped working.
Replace the Battery
If you tested your battery and think it is damaged, then you’ll need to purchase a replacement. But before you throw it away, try your weed eater with a new battery first. If you are still having trouble, then it is probably a different problem.
So, use your new battery until it’s dead, then charge it. If it doesn’t charge, then you need a new charger. Also, having two batteries isn’t a bad idea anyways.
Parts to Replace a Weed Eater Battery
Repair the Battery Connections
If you have corroded terminals, then a piece of sandpaper should be enough to repair the connection. Just sand off the corrosion and give the weed whacker another try. If you have terminals that can’t make the connections, then you’ll need to bend them out if you can. I find a small screwdriver under the terminal, and a little force is enough to bend the connection back out.
Tools to Repair a Weed Eater Battery Connection
Replace the Trigger Switch
To replace the switch, you just need to remove the connection and replace the faulty part. If you happen to have soldered connections, then you’ll need to take a soldering iron and free the wires. Then you’ll need to re-solder the connection onto the new switch.
This is the part where you might find it hard to get hold of a replacement. I’ve heard that a lot of people have trouble getting hold of replacement switches unless it’s a brand like Stihl or Echo.
Parts & Tools to Replace a Weed Eater Trigger Switch
- Replacement Switch
- Soldering Iron
Repair the Motor Connections
The connections on the motor are similar to those on the switch. They can either be soldered on or fixed in place with a connector. So, if you have corrosion, remove the connector and clean up the terminal using a piece of sandpaper.
If your connections are loose, then you can use a pair of pliers to pinch the connector. This should close the opening on the connector and give you a much tighter fit.
Tools to Repair a Weed Eater Motor Connection
- Soldering Iron
Replace the Motor Brushes
If you search on the internet for replacement motor brushes, you should find a result for the parts you are looking for. Once you have them, you’ll need to remove the old ones like you did when you were inspecting them, then install the new ones. You might need a screwdriver, but you might be lucky that they just clip in and out.
Parts & Tools to Repair a Weed Eater Motor Brushes
- Replacement Brush Kit